This invention relates to a wire bonding tool having a tip made of an electrically conducting silicon nitride containing composite and a metallic stem.
In the wire bonding industry, a wire bonding tool is used in an ultrasonic wire bonding machine, which, through this tool, imparts energy to the wire which is being bonded to a pad on a printed circuit chip.
The typical materials used for this application are cemented tungsten carbide or titanium metal. The advantage of silicon nitride is in its longer life and the superior bond strength realized in the wire to the pad joint. The toughness of silicon nitride is lower than that of the current materials which are used in bonding tools. Monolithic silicon nitride based bonding tools cannot withstand rough handling.
Therefore, it would be desirable to produce a bonding tool which has the long life characteristics of silicon nitride and the toughness of metallic material.